Hello,
To run Windows 11, you need at least an 8th Gen Intel Core i5.
You have a 6th gen Intel Core i5. That's too old to run Windows 11.
However, you have three options:
The first option is to buy the Extended Support Updates from Microsoft for $30 a year for every year you go (more can be foundhere).
The second option is to upgrade to Windows 11 on unsupported hardware. Although not recommended, you can upgrade to Windows 11 on unsupported hardware by making some registry edits. You also might run into compatibility errors as well as a slow system.
The third option, which you said you can't do right now, is to purchase a new computer. This option is actually more recommended since you can enjoy better hardware.
Now back to the second option:
To install Windows 11 on unsupported hardware, I would first recommend making an entire backup of your system just in case something goes wrong, and then once you are done with that, follow the steps below.
Open Registry Editor and push File > Export and then make sure All is selected under "Export range". Save it to a location anywhere on your computer, and then press Save.
After that is done, at the navigation bar on top, type this: HKLM\System\Setup\MoSetup and push enter. After that, right-click inside that screen and press New then "DWORD (32-bit) value". After it is created, give it the name AllowUpgradesWithUnsupportedTPMorCPU exactly as written, and then press Enter. Press enter again and give it the value 1. Make sure that Hexadecimal is selected as the base, and then press OK. Make sure to type everything as written.
Then, restart your computer and then use the Windows 11 Installation Assistant, the Windows 11 ISO, or the Media Creation Tool. All three of these options will get you to Windows 11, version 24H2.
To use the Windows 11 Installation Assistant, download the Windows 11 Installation Assistant and then run it. You should see some prompts telling you about Windows 11 and what it'll install. Let it download and install 24H2.
To use the Windows 11 Media Creation Tool, download the Windows 11 Media Creation Tool, and run the MCT. Once it finishes loading, push "Upgrade this PC Now". Let the MCT install the Windows 11 installation files, and then let it check for updates, and then let it install Windows 11.
To use the Windows 11 ISO, download the Windows 11 ISO, (you can find it here, scroll down to where you see ISO for Windows 11 x64 devices), mount it, and then run setup.exe (if you see a UAC prompt, push yes). Follow the prompts on-screen and then let setup.exe update and install Windows 11, 24H2.
All of these steps will get you to 24H2 and will take a while to install. It's best to do this at night when you're not doing anything important. Just make sure to save your files before you start.
For more information, you can refer to https://learn.microsoft.com/en-us/windows-hardware/design/minimum/supported/windows-11-supported-intel-processors.
Let me know how this goes.